1. Field of the Invention
The present invention relates to a storage control device and a storage device error control method.
2. Description of the Related Art
For example, governments, official agencies, local governments, enterprises, educational organs and the like handle large quantities of numerous types of data, and therefore control data using relatively large-scale storage control devices. In such storage control devices, a storage region (RAID: redundant array of independent disks) that has redundancy is constructed using redundant information, and data is stored in this storage region (Japanese Patent Application Laid-Open No. 10-149262).
In such a storage device, the data is divided into units of a specified size, and is stored in dispersed form in a plurality of storage devices; furthermore, parity data is also calculated from the respective sets of data obtained by such data division, and this parity data is stored. As a result, even in cases where some single set of data is lost, the lost data can be restored (recovered) on the basis of other data and parity data.
For example, in the case of a hard disk drive, a series of sets of data are written into a plurality of sectors. In cases where the writing of data into a certain block is lost, so that the write processing is interrupted, the planned data is not written into the respective blocks following the interrupted block. In this case, the loss of writing should be detected for all of the blocks into which data has not been written.
However, it has been discovered that a phenomenon may rarely occur (depending on the trouble mode of the hard disk drive) in which the hard disk drive responds normally in spite of the fact that blocks that have failed in writing have been generated, and other blocks that are continuous with these blocks are in an unwritten state.